<template>
    <!-- 商品分类导航 -->
    <div class="type-nav">
        <div class="container">
            <!-- 事件委派 -->
            <div @mouseleave="leaveShow" @mouseenter="enterShow">
                <h2 class="all">全部商品分类</h2>
                <transition name="sort">
                    <div class="sort" v-show="show">
                        <div class="all-sort-list2" @click="goSearch">
                            <div class="item" v-for="(c1,index) in categoryList" :key="c1.categoryId">
                                <h3 @mouseenter="changeIndex(index)" :class="{'clu':currentIndex ===index }">
                                    <a :data-categoryName="c1.categoryName" :data-category1Id="c1.categoryId">{{c1.categoryName}}</a>
                                </h3>
                                <!-- 二 三 级 -->
                                <div class="item-list clearfix" :style="{ display:currentIndex ===index ? 'block':'none'}" v-for="c2 in c1.categoryChild" :key="c2.categoryId">
                                    <div class="subitem">
                                        <dl class="fore">
                                            <dt>
                                                <a :data-categoryName="c2.categoryName" :data-category2Id="c2.categoryId">{{c2.categoryName}}</a>
                                            </dt>
                                            <dd>
                                                <em v-for="c3 in c2.categoryChild" :key="c3.categoryId">
                                                    <a :data-categoryName="c3.categoryName" :data-category3Id="c3.categoryId">{{c3.categoryName }}</a>
                                                </em>
                                            </dd>
                                        </dl>
                                    </div>
                                </div>
                            </div>
                        </div>
                    </div>
                </transition>
             </div>   
            <nav class="nav">
                <a href="###">服装城</a>
                <a href="###">美妆馆</a>
                <a href="###">尚品汇超市</a>
                <a href="###">全球购</a>
                <a href="###">闪购</a>
                <a href="###">团购</a>
                <a href="###">有趣</a>
                <a href="###">秒杀</a>
            </nav>
        </div>
    </div>
</template>

<script>
import throttle from 'lodash/throttle'
import {mapState} from 'vuex'
export default {
  name: 'index',
  data(){
      return{
        currentIndex:-1,
        show:true,  // 控制分类列表的显隐
      }
  },
  mounted(){
      //this.$store.dispatch('categoryList')  获取三级分类的数据不要在这里执行  放到 根组件执行一次 存放在仓库里 切换组件 直接从仓库里取数据
      // 不是 进入到 home 组件 把 show 变成  false 
      if(this.$route.path != '/home'){
          this.show = false
      }
  },
  computed:{
     ...mapState({
         categoryList:state=>state.home.categoryList
     }) 
  },
  methods:{
    //   changeIndex(index){
    //       this.currentIndex  = index;
    //   },
      changeIndex:throttle(function(index){  // 节流
         this.currentIndex  = index;
      },50),
      leaveShow(){
          this.currentIndex  = -1;
          if(this.$route.path != 'home'){
               this.show = false;
          }
      },
      enterShow(){
          if(this.$route.path != 'home'){
                 this.show = true;
          }
      },
      // 编程式导航加 事件委派 + 自定义属性
      goSearch(event){
        let element = event.target;
        let { categoryname, category1id,category2id,category3id} = element.dataset;  // dataset 获取自定义的属性
        // 标签上有 categoryname  一定是 a 标签 
        if(categoryname){
          let locaton = { name:'search'}
          let query = { categoryName:categoryname}
          if(category1id){  // 一级分类
            query.category1Id = category1id
          }else if(category2id){
             query.category2Id = category2id  
          }else{
             query.category3Id = category3id
          }
          if(this.$route.params){
             // 有 params 参数  也要把 params 参数带过去
             locaton.params = this.$route.params; 
             // 整理参数
             locaton.query = query
             this.$router.push(locaton)
          }
        }
      },
   }
}
</script>

<style lang="less" scoped>
 .type-nav {
        border-bottom: 2px solid #e1251b;
        .container {
            width: 1200px;
            margin: 0 auto;
            display: flex;
            position: relative;

            .all {
                width: 210px;
                height: 45px;
                background-color: #e1251b;
                line-height: 45px;
                text-align: center;
                color: #fff;
                font-size: 14px;
                font-weight: bold;
            }

            .nav {
                a {
                    height: 45px;
                    margin: 0 22px;
                    line-height: 45px;
                    font-size: 16px;
                    color: #333;
                }
            }

            .sort {
                position: absolute;
                left: 0;
                top: 45px;
                width: 210px;
                height: 461px;
                position: absolute;
                background: #fafafa;
                z-index: 999;

                .all-sort-list2 {
                    .item {
                        h3 {
                            line-height: 30px;
                            font-size: 14px;
                            font-weight: 400;
                            overflow: hidden;
                            padding: 0 20px;
                            margin: 0;

                            a {
                                color: #333;
                            }
                        }

                        .item-list {
                            display: none;
                            position: absolute;
                            width: 734px;
                            min-height: 460px;
                            background: #f7f7f7;
                            left: 210px;
                            border: 1px solid #ddd;
                            top: 0;
                            z-index: 9999 !important;

                            .subitem {
                                float: left;
                                width: 650px;
                                padding: 0 4px 0 8px;

                                dl {
                                    border-top: 1px solid #eee;
                                    padding: 6px 0;
                                    overflow: hidden;
                                    zoom: 1;

                                    &.fore {
                                        border-top: 0;
                                    }

                                    dt {
                                        float: left;
                                        width: 54px;
                                        line-height: 22px;
                                        text-align: right;
                                        padding: 3px 6px 0 0;
                                        font-weight: 700;
                                    }

                                    dd {
                                        float: left;
                                        width: 415px;
                                        padding: 3px 0 0;
                                        overflow: hidden;

                                        em {
                                            float: left;
                                            height: 14px;
                                            line-height: 14px;
                                            padding: 0 8px;
                                            margin-top: 5px;
                                            border-left: 1px solid #ccc;
                                        }
                                    }
                                }
                            }
                        }
                        // &:hover {
                        //     .item-list {
                        //         display: block;
                        //     }
                        // }
                    }
                    .clu{background: skyblue;}
                }
            }
            .sort-enter{
               height:0px;
               //transform: rotate(0deg);
            }
            .sort-enter-to{
               height:461px;
               //transform: rotate(360deg);
            }
            .sort-enter-active{
               transition:all .5s linear;
            }
        }
    }
</style>